Fig. 1
From: Implementing a blockchain from scratch: why, how, and what we learned
Overview of the setup, including nodes, the clearing server, the app, and a conceptual view of the blockchain. Each customer possesses an app that is connected to a node (for sending new transactions and receiving confirmations) and to the clearing server (for billing). New transactions (denoted as Tx) reside in a pool of unconfirmed transactions until they are mined by a node and appended to the blockchain. The clearing server retrieves data from the blockchain and sends billing information to the customers’ smartphone apps